Solar Thermal Measurement Detective Work (Aug-Nov 2009)
The problem: Implausible values reported by meters installed on commercial solar hot water systems.
We managed the installation of five monitoring devices to provide information on solar hot water system performance for the state of Wisconsin Focus on Energy program in 2009.
The Focus on Energy Program wanted to provide installers and consumers with information on field performance of solar hot water systems for both residential and commercial applications. Volume and temperature data were sent to a hosting service for transformation into data displays on web pages. We observed volume values that were impossibly low for two commercial sites. We carried out detective work that involved swapping metersand coordinating communication among engineers at the hosting service, the U.S. distributor of the meter and technical engineering support in Sweden. We established that the commercial-scale meters could not communicate correctly with the hosting service (unknown prior to our investigation to either the vendor of the meter or the hosting service who had previously worked together). We determined a software solution to enable proper recording of information in the hosting service database and proper display of information on the web-pages, enabling the program to capture correct data and maintain project schedule.